In the current used lock, the door handle is combined with the lock. The function of the handle is to reduce a lock tongue of the lock seat inwards so as to separate from the lock tongue seat to achieve the object of unlocking. An outer side of the door lock has a lock hole for receiving a key to rotate therein so as to achieve the object of locking and unlocking. In such a structure, the locking of the door is controlled by rotating the switch at the inner side of a door. It is not a convenient way. The process in manufacturing and installation is completed and the cost is high. It is not an ideal way.